Objective: To evaluate the effect of a modified crushing-cercariae escaping method on the detection of infected Oncomelania snails in the field.
Methods: A snail survey was carried out in Jingzhou City in the spring of 2011, and the villages were randomly divided into several groups, the coincidence rates, detection rates and the labour cost of the modified crushing-cercariae escaping method and crushing method were compared.
Results: A total of 14 snail spots were surveyed, and the coincidence rate of the two methods was 100%. In the spring snail survey, 539 villages and 3 536 spots with snails were detected by the modified crushing-cercariae escaping method, and 671 villages and 11 375 spots with snails were detected by the crushing method. The detection rates of villages with infected snails of the two methods were 25.79% and 28.46%, respectively, the difference between them was not statistically significant (chi2 = 1.079 5, P > 0.05); and those of spots with infected snails were 5.57% and 3.66%, respectively, which had no significant difference between them (chi2 = 95.464 1, P < 0.01). Compared with the crushing method, the modified crushing-cercariae escaping method reduced labour cost by 87.86%, and saved 12.95 person-days per township.
Conclusion: The modified crushing-cercaria escaping method can identify the spots with infected snails quickly and accurately with less labour cost, therefore, it is suitable for detecting environments with infected snails in batch in endemic areas.